SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df6811f262936cdd0f755a53aceb0f8fc63516dd4d0c5f9fbb4fd24826e841ca' 
  AND token = 'OXsk/oBMndOrLiej9nglBsYrfl1xK5EqmSwlgypkibA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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