SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbe331d448fc004fe45a83984a6c2335682775d540bcce608d3021f8bff1649d' 
  AND token = 'TQ+HieXb1h+COBGzJksu1R26jxwgKOVCCyREHI1MMGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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