SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abc22054b01c995084a952dd282673ebe47492f97fd17d731b5ebb7439757fc4' 
  AND token = 'AOdtbsqcKvEd35DP9gpqoTHBL+pCsYGCvkzMHnk5Eus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}