SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31f9bf07104736be7cdc44c307442b623f2965020b688eae6c3aaaed64e41f29' 
  AND token = 'cHFIxdq4/f+5bmzgbfh1hnqZUi0Ksj0Qd1NuXHFs8bM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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