SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95b747d231af86f061d9b40813ecd5ace6643513d0e326df8fc706deeaf98091' 
  AND token = '9WSa1SzcBYmUcC1lZhM4zBEfZRPzmdCa3n+KtbJPVXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}