SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcce5b0953fd840f37386f6d41159c4149a1b40e982a8689c80e2a5375284d6d' 
  AND token = 'JFXZYKoQFtBDZ1t/wWYaPHMhB7P7ln/WR8eYUuRWR5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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