SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7d0ed8a752ffd302dc396d17d59b572b37a205e03ffef74c111be93f01cda31' 
  AND token = 'neXIzDS5gWmGJKg0psejG/mI6TvwqjFHXWKf7+oqxnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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