SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44d73e6f1dc038d9ba69ac5bc816217f2f50f838346c5c1bdda8849760491907' 
  AND token = 'h1Me8XecL3JANU7jgewmZ6knOumXpgBniG19WdPRQ64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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