SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de58463a11ce7dde96ded1362a3e128467bd715079e1e1ad12903cd07ba61dac' 
  AND token = '2ik8zG1BF7XO1aE7ndcRMTkg7VEt9m4E/fUTWW8oVZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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