SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e951cb154812ae6a536fe58706308c4d13b6de739950b815fb37e08fa32c20cd' 
  AND token = 'eKaZpoZ3jcaAnmc5j9bwVLaRicLyBFotjQHTRtbN57w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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