SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '475e54ba5430652de62d71c2abc193bfeff3d8aa1af452aafaee3dd8faacfacd' 
  AND token = 'RC40u4I5OGOLVLvk2LAgEuNVQ2b1ExbVCvI0jZ74HPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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