SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c11220049cb194be9b842864d761d65c2275b638dfe41c2b9f29b0c9bbfe281d' 
  AND token = 'uxyobQU1khoPOvM2lYDKGECzEbRZFdmU9XymGPvDjF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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