SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edc1a82badc675bb6ccd174d848cebcd1a9b3fbb05095400d941acb8caf468de' 
  AND token = '1n62o4tWY958ogsrH3fz5D1aW9PFWgwa/KyAgj3UxYU=' 
  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"
    }
  }
}