SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '664fecf833fc93ab610ebf7ab7ca2d7b1541fbf9a5583e2d3e1f5d42a4322360' 
  AND token = 'YK3zMsOEZCBom9mDNVufoAPpLHDMjoJ1aiuTkkoDFBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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