SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6e40403b536d0dc3eb0196dc031ff7ad64d72116fef1d9876f8c6532d463ea33' 
  AND token = 'vOVgy+flGDQGvnGOZoh5f+deKdkKl0QrKOU47I61j78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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