SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fdfd02a3551fbb39b8d0a6e0ffda6df39cdbb99091d7ea0a964b5de3f7c7d814' 
  AND token = 'Vo0ClqzvZQ2rs+MZuA70Wx61hf+jZf8FmIalHBuAwoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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