SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7e0ac8b78963d51e844dd815e1204e2ff38407b3a6cdeb10175ee842a0d705f' 
  AND token = 'X29Fu9wroe9KptOEaH/pQMshSHOjOD4IpUWc82bWNyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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