SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '760b5e30aea0205571d1698a7209f9abe51c1b96f6a99b7711881cc0bebfcf0c' 
  AND token = 'ZsrH0v3132L2oHFA4MJLXG2crtQxNmx4Bf7pom1eBJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}