SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa9cba28d6f12f4802ee91e0b6987a0ecca47f80404316c27bfc812df85e73f7' 
  AND token = 'jvu2zMXGxckhTrxHBUTFrj1iR3eCgPMepWnv+5ejyfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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