SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be58967ef8ac0fb0106278f136327001b0489eb7eec0bdcd919805c501c3c5c9' 
  AND token = 'PfGYFPRNpKKF8kg49jU8IhJaU9czDFVMnh9kQ9+HVNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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