SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cee94dd46bd8dc7cbc48d5fd6d0c43475e8288632d8cb841c4e1498f2853f99f' 
  AND token = 'ZCJJkRzOmlKt//zw9HeoSTumhmj6ry2nnlhSC2rKvGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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