SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a7b9f64119c53c1d5ae22a47df0957bd1707a62dffeb7c5320fc758aede2f99' 
  AND token = 'vizlvLHSohp8Djc/YVbiUw8eBbPG4XHYSXsR4Gy4Wn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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