SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ecef75503b796b7c4e0c1aa556b0829602729b9a9dea1f6226ec220cddcf274' 
  AND token = '/8uR5ycywfwwFeIHogq3STKFK3wVIFTavbk+urbisSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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