SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad22d852aec6a5a45239e8254b4a3182363e6bb282df1645bb947db62f70673e' 
  AND token = '4WSy/Ny+tgbkObiG7qG4A8/Y7Y/tcyqFOkYSsnIW2Y4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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