SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd4a90a4882704c797e39dcf308115ed280460e4c85e0792c4c6d8340b70057a' 
  AND token = '85nqsGNyd4RVxJgWdKzKa+CdG2mDphbqlmRgJSf76os=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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