SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83abe557de0fd7cc120cc66208c5481ad24081b8ea80525e63601990429c6af4' 
  AND token = 'hkYyFCw2LKxKPVK/L0t5Fgq6ItSKwjUPa/TGv+ee+xY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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