SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d635ee808c41903dfb9dad46b95f7a69e776e01b3988ecbdc9b03cba184ded0' 
  AND token = 'xicTnjM7U0ghJWCvOTNc4eJcKsDcLlv0XtKg+90nPIE=' 
  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"
    }
  }
}