SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '085ce6c872f25fa839556f68266b51208ea36beeca8020aabe26fe6282317586' 
  AND token = 'clnPZM16AHRJpfNnv245YE8QAPE/tpGrw0qUMKjhWds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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