SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e93e4483057420829371c4dce10f922053f3eeec7664caa2899e87064f6c734d' 
  AND token = 'TnbmteTrcBptIo6AnZWQcilfPzmFCZDjfVVcPn8mu8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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