SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2df7c4439009f3c3b8f95c8dbddb5fe6961427e2372efb5f0d08769255347f61' 
  AND token = 'tfaokqWrdEEsPixeEwTginD8gHBovZHeXdhq5/CsMUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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