SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27a6a975c21ad7f7ccf6ada114342d9167d6d0b6bd8d753aec59483f69043501' 
  AND token = 'LhaqSFGRJHan9+23RWfE83vLe415E9QMA2DDUQLdAYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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