SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dcabf961cb2956320881343584ad5354a10334089cf67457e1f18df6ceee039' 
  AND token = 'ATkxCXe2Y2Jy6ZGv/m9S7CsHE8GrIEU2orzBA4DBQsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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