SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b4053b436b4e1fc212d5367996182aaa3bc1a6058f55025bb98b2598efb9c71' 
  AND token = 'NIl3vtGPlwISpmMH/zw5aGLjxlDRUv2dQB+GHgsSTWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00117

JSON explain

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