SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a73c72ccb41b766ce1acd7689a1a0a7bdbff6a4f8143670d107ffdb958d8f811' 
  AND token = 'W/aOleCXEs3xGsj8K1SmnoYz1TcIZZ9ri+aPUaxDciQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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