SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af02514106a3b3d6fb6ee1269c80ab9aeb82335a4f8d41bf63b9f37f2396b3ea' 
  AND token = 'xj7XSFX3AI19kaywnKXmjz1OqLGRBm8DGZQK+KxFvUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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