SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f048c4f842ad03e4694fbb5d9f8fb7016a89e2a9b6470f2d69044651e1e924a' 
  AND token = 'SypLCVu6wbFCL0hKVytj7KBHrh22JA2IPAzfBuQlXZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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