SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b97eafca4ecdf18844164fc105795bdeabe54b85acabf8ede57deff784c6d0d8' 
  AND token = 'JMJpjWDzGfFqzOW9q00mKCWLDM4V20ag0XOeC+E0Ls0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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