SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5b72cf88de76b7e7f8c07becb159dbccb517044f2e4ef5e1762419b319be884' 
  AND token = '6yHcW/YuflKqC7QbRvmGmZIKybqVBZaVrjQldgIFkkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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