SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78895544d1991d09bc561d347959220f697d689fb844a7e841b93e89e6717b64' 
  AND token = 'NhQ4XH97OJ92++kFGPg0qtYr2+NeBbUroVHszycN48w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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