SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fed830070fe2874a8cda915bae54d7db7b4b996f210bc8841e803fe44ebc69ea' 
  AND token = 'U6ZiSYdC/ckwjVNR4gCWhtuS4wuFECgVvhggZP06JuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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