SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd261dfb155177fb624871dd0570dbc707dea6803c199b8b8af82ea218fe42d6a' 
  AND token = 'lVV1qVvI5r1zCpSnRQZjBfBUKYp6sSrr4JdfNwReCgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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