SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2a37dae5251db6b209d708cb968b4798591df807ef26b620e5e4c521b504f95' 
  AND token = '1sGUnWRO/Vr70/6f4gN6qrr2cGTf2xWptKvzovb6PvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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