SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '324ff6d3bb283aa66587ab56786977613b15456263f344523fa00214d6f4fc4c' 
  AND token = 'hDpVMVkXjWktngoNkxSA4jghumdiXuKGQXQZ1UKKYxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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