SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0103251a87ce605c5a44825e40253d0bced145616ac3d52788fa746bb663e269' 
  AND token = 'GHu9XaCKDTX6/ZolAqOoEtAVVYjNoN4aHDSCxxqFwCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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