SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ae6b1998327fbe1d43cdc86d19922b180bb0beb73cf42c9f92ad39473acd00d' 
  AND token = 'UI0Ztr/fKW7BLoGwkJrPIwMAkvQDz3bO5weESR5lZPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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