SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e4ec13e6069ec711b0a803400b1c539767f43131cf23f69620d267b6e47ef0d' 
  AND token = 'IxM2UPWM0/g6Bg2GPiuFcXsVwfvblb/ADt//fE/RTX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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