SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4ab7ea4a8f8c5fd586f1bb766e730abeb7ed7704bf6f5304d6e3f7d6255a85d5' 
  AND token = 'VjVIxTerubzz0aCHxSWadFU4rBYoYbd8acThiuFVgQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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