SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f381834785a6ef934a8babe2617e68fb73e7dcedf9bb91b960cae56dc66cc172' 
  AND token = 'lxDpXPNAYFaimtFC0yEUO9imY9RhpphE6JNqd+kg5Nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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