SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c57a87984ff0b0b8012760ea54711d67e9c308dc431d8738f2adb78efc1c7481' 
  AND token = '61IRxbh1/K+4hbZOT72ugCPfGKTRuzUwJtkOq3Xiq3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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