SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd6a40dabdc39120c64c3d18bb97fe0b0f3a600240699ab955d734375ece2c9d8' 
  AND token = '9yRD2j0NoB7sBnlRct9MCe1ZDpA5+kjjPUEUzzQSuKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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