SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3c6c33fb3c2b444701de2c8a72713bc907f025fd4d3edd0bf673daf44dc0687f' 
  AND token = 't8OQ0kVGvd4PtFSvG81PqmvpIvquDxNZS+ys9mqnDNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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