SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54d5a66323b44a77c7af120b4956ca631f8f46228d3b14f94338d4646a3afbbd' 
  AND token = 'Nbxo9lTsOpncGhmI31cvqrBBwkVf0h0b2S+nF4CMOCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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