SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '648e93ef141f62c2ec7b0e0cf841c723b349a491b80bd8fb061821c343642b1e' 
  AND token = 'SCMG0aONNdvZg55VFhbnYUunfivEafZEafOtnuO+DLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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