SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0bc8027726c6ed11779b97c2f048343a81c9507b925122648181ee5785e3a76' 
  AND token = 'HRO4Ntd7clvAwbfpXuoy5jx9ByHB9P46uMw4jHTXGMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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