SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e1d18b1371a1b94b9656a8fc640273ea715d8120cb49e2ddbda58e045000c80' 
  AND token = 'niGXTkMkTvrsTdUKBdtET9wIwvbxQbLNsuLmAE4szcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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