SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '425ac717e2f76424b1f890a0fc826c52ed5a35aa1f3fde8c6c99ea4d235b3444' 
  AND token = 'iEcxsb7ePq/YIPiorJsiIk9YOQuyAkBZGyv43oO69Rw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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