SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '032fd5ea2ccb0f0087a0ed59888f1db2c3abc08b267c8bcd9691b11447e4d84b' 
  AND token = 'b/1LeyKi8gmrfp8pHiBrXWxMSFn25Vd1lZRra2G38qU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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