SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfffe974326876930adc4c21992c88073629ca275865a8ff7b8e15193410bdff' 
  AND token = 'hEHUsH3FhfgdDy/i3vZZjeGq9Dhzgw1gA33/LO/fCC4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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