SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a361419e7dd63f8ce8229d6d7e30d15a0aca3c2fbe983af91b2059311bd9f011' 
  AND token = 'aN1gXUD582U1JARw7toP0n+AZ8XQU/k6us8kxRZZdwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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