SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '944e18a090c477b9a317bc8a6975ffb91f61e248768fd7610204258f4a3a9106' 
  AND token = 'xWUBvbpRqbqMwnOGGJ2kd0ehC4Zo7xmzyyvExeKyHuQ=' 
  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"
    }
  }
}