SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8622cd8be5b4a0a84ebcd036f51d540b42c239a06277118c1b1d5f5768bbc147' 
  AND token = 'ZyJ0PpT6TTKNbuuz/gduVerkj/QFLl8ywMLoB0VNlVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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