SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5de99ae17a454f093c4975ef180f824fd10dc83a337bd13c3921b708f0c5d638' 
  AND token = 'RfCRZ0FFVD/12khFfThmIZek0VBqd3KoTprO2pduPA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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