SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6fe94bbf2d4553cdbf59f7f91e58579c3def1bd197d2432739fc5e72bfd1295' 
  AND token = 'BwUmv8NYBdNHrjK8J4wUuctzHkbm66RJOA9+RCkgeg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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