SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '91f7138abbbe1da250f56324ddcbe56f4aa631458613ea70851e98472c35ad67' 
  AND token = 'pCs+szMhBDym+uaLPF3OBSVCzpmBYaOwTe37Q925WLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}