SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e259665c4270fef6f6a3526372b8918f9c8b4de815ce35a79ac2c8dc16f31436' 
  AND token = 'VOr0lBha7FskdDVbxnIKMwuSnDARLjSQj+4nrYb3gCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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