SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '732976389b0a02f4c9b0948fab3ac35cffa8d9448bb2a814beb537d4577277b9' 
  AND token = 'UE/qC/HW/L1JG8ASdBpFeXHnZr4jIUgUM6A+akL4vBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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