SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a731d086aebd80fe2195fbefd2fa8b73555694ebf4c0a4d22f5e9aabf371fa9' 
  AND token = 'nhIz5RLCKWpmMFtzvh9O0CHdnYXwhlSxWhUL4lbN/zQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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