SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fcaddf841ecf365fb7369530a4f6244bd65d10db8b124939733fa1c8b18dbc3' 
  AND token = 'nAH3/00rKAUwQ/e3BlODL6Ua1icZBBFdaOLyPMoP1pU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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