SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37822f6c1963b80605dba738276fa15467535c0ef4ac9d2f3bc394f2acc64c49' 
  AND token = 'iavOBtdn4/rEaH9nCDw0G/Z8hzQyCvW63gCZwSxB3hg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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