SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '56aa2f601bdac440a49b2c36042c5fb2fcee5590758023d69b66eae8806dc271' 
  AND token = 'ohqIDeFAtd48CEse2v6UHGRZeG64o8VQ53w92ZaCuzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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