SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03ce98218efc0fba7747fa0eda87ca6f8620336dde2502befe0b37b550210305' 
  AND token = '2QDh6550H1EsK1bFbmrphqgBOo1+OOvYxrPIwHhaXjk=' 
  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"
    }
  }
}