SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79c560f0985d10fc51247dd3979d84f587917167c2ec427f6822b5a4209d2362' 
  AND token = '1NnhTp+gAZskX2Tq/wk9Nd5J1nvygl7llOKplQ4OVwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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