SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f9d89f73038510554d30a924cd0f276a239f50f1ca235d7ecb4345845109871' 
  AND token = 'UHh9sFbaZ2DQsbWC5EKvdDuUw7ygbcO2JR8W/N5C6iA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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