SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd54154f44c6ada6554d0b50cd398cb4f9fa2a71d67b8fb8c48695710b398541' 
  AND token = '6/PRlvUNnZFUXZJzzn9dlH902Oz/KrLI3/h1j7KjJhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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