SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae419f9abecf68e97719633e594dbca03e03453422dd819a78bb141ba9360d12' 
  AND token = 'MCt7ZgnjjZWIves2gm8ZY3MT9TZfAiTwD2KLXFE0gg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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