SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef47d2d0ee7af453d6815a79873ac11cd729bdefa39afa407512178ae12f3ce8' 
  AND token = 'xVzxWFcnkOiDqn/g1mbW7BOq8gplWFwiXEdc2PR2xX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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