SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a84fceefa0707360dd8393f078ffe538eb22ddf4a5ba470c9b8ad90c937f03f' 
  AND token = '3IsTe57tK+Wu0A+LCyvGab51s88OLESqhoeYuztaE+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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