SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6aa8ad03dbfb313f4db1e355f544005cddc6c1ce57844b61bdba68bf58093ef' 
  AND token = 'lZ5Q96ZDv5NxjOIfN6VZTgYErcs3KTihgNI/aNe64HM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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