SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b1f43d1fbb9e008af42f823093cf25a9454d14ee1426ebe759056f2f7eaa953' 
  AND token = 'mr9aF5IsWqHW8ArjoVvKIYx+nEnx3KDSC+WqruoJPt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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