SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbebcd801565d2ef0c5375f16ee0ae08a6665ed81c3abb9b72444bf81354d53d' 
  AND token = 'FUlnITpeSIphEfDZE6fm5SwF3/+9NYUVq32yM/vcnZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}