SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c1390c62768a5010d4ec3d6c18ca6ea950a9787854f8d5659ac68da751b0eb87' 
  AND token = '4kBqABHLnvVN64FQrBYYCGB5YZSVtF3Ig0A/AQrxLPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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